Yes - go to the "User Page Display" tab of your Profile and, on the left side, there is a drop down box next to the title "Current Mood." Select a mood from that drop down menu.
FAQ #94: My user page states I am new (or agressive), can I change this?
FAQ #601: How do I set it so my 'Full Name' is not displayed on my user page?
Go to the "User Page Display" tab of your Profile (this link can be found on the upper right of most deviantART pages). On the left hand side ("User Page Elements"), there is a drop down menu for Deviant Type.
FAQ #168: How do I add a deviantID to my devious information? What is the recommended size of a deviantID?
FAQ #4: How do I edit my Devious Information?
You can either make your own, get one from the Avatar Gallery here on deviantART or get one from another site. Please note that avatars found in deviantART's Avatar Gallery are not always free for use. Make sure that the avatar you wish to use is for free use. The avatar must comply with certain restrictions - see FAQ #147: How do I upload an avatar? for this information.